Tires for rollers designed for compacting soil

ABSTRACT

A tire for rollers, particularly vibrating rollers, designed for compacting soil, which has a cover made of even sections. The cover sections have the shape of a triangle or trapezium. Adjoining sections each share a side of a triangle or trapezium of the same length and are arranged in such a way that on the face of the tire, running in the direction of its circumference, the point of a triangle of a preceding cover section is followed alternately by the side of the triangle, situated opposite the corresponding point of a triangle, of the adjoining section.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a facing for rollers, in particular vibratoryrollers, for the purpose of ground compaction.

2. Description of the Related Art

In comparison with the frequently encountered, known roller facingswhich have a cylindrical lateral surface and have poor ground tractionspecifically on upward slopes, but also in the case of unfavorableground conditions, and tend to slip in these aggravated operatingconditions, facings as described herein have the advantage of morereliable traction in these aggravated conditions.

In the case of the known facings of this type, which up until now haveonly been used for static rollers, the lateral surface is made up ofrectangular lateral-surface sections, of which the long side edgesextend parallel to the axis of rotation of the facing. Although thisform of lateral surface effects the more reliable traction desired,because the bending lines, which extend over the facing width and arelocated between the planar surface sections, dig into the ground againand again, the increased traction lasts only for the duration of theengagement of such a bending line in the ground, whereas there is anincreased risk of slippage when the planar rectangular surface section,which follows an engaging bending line in each case, rests flat on theground. For this reason, facings which are formed from rectangularsurface sections are not suitable either for use in conjunction with avibratory roller in the case of which the facings are made to vibrate bya vibrator unit which produces a circular vibration or a directedvibration.

The known facings with a lateral surface formed from rectangular planarsections also have the disadvantage of extremely jerky operation, thenon-uniformity being all the greater the smaller the number ofrectangles used to make up the lateral surface.

In order to improve the traction, the prior art has also proposed toprovide the facing surface with grouser bars. Apart from frequentlyundesirable excessive deformation on the surface of the ground which isto be compacted, grouser-bar facings have the great disadvantage thatthe material which is to be compacted can clog up between the grouserbars, and the grouser-bar facing is far more difficult to clean than afacing with a surface which is smooth or is made up of planar sections.

Taking the above-mentioned prior art as departure point, the object ofthe invention is to provide a facing which is also suitable, inparticular, for use with vibratory rollers, which is distinguished bytraction which is considerably better than that of cylindrical facings,and also than that of the known facings with the lateral surface formedfrom planar sections, and additionally by rotation which is considerablybetter than that of the last-mentioned known facings, and which is alsovery easy to clean.

OBJECTS AND SUMMARY OF THE INVENTION

The above object is achieved by providing a facing for rollersconfigured to compact ground. The facing includes a lateral surface thatis formed from planar lateral-surface sections in the form of atriangle. Adjacent lateral-surface sections each include one triangleside having an equal length in common. The adjacent lateral-surfacesections are arranged such that, in an alternating manner in thecircumferential direction of the facing, a triangle vertex of apreceding lateral-surface section on the end sides of the facing isfollowed by a triangle side, located opposite a corresponding trianglevertex, of the following lateral-surface section.

Alternatively, the triangles can have a truncated end to form atrapezium such that the adjacent lateral-surface sections each includeone trapezium side having an equal length in common. In this version ofthe lateral-surface sections, the adjacent lateral-surface sections arearranged such that in an alternating manner in the circumferentialdirection of the facing, on the end sides of the facing, a shortertrapezium side of a preceding lateral-surface section is followed by alonger trapezium side, located opposite a corresponding shortertrapezium side, of the following lateral-surface section.

The configuration of a facing according to the invention means thatduring operation of the facing, more or less in any angled position ofthe latter, at least part of the length of one of its angled bendinglines extending over the facing width is in engagement with the groundand thus, even on upward slopes, ensures uninterrupted, essentiallyslippage-free traction. In comparison with the facings which are made upof rectangular lateral-surface sections, and in the case of which theindividual surface-area sections strike the ground one after the otherwith a jerking movement, the seamless engagement in the ground of thesuccessive facing bending lines between the planar lateral-surfacesections also results in considerably more uniform and smooth rotationof the facing, and, in the case of vibrator units being used, the flatlateral-surface sections transmit the vibratory forces into the groundwith particularly high efficiency. In this case, the surface-area loadis similar to that in the case of vibration plates. Added to this is thefact that the high linear load at the abutment locations between theindividual planar lateral-surface sections aids the compaction operationfarther.

The planar triangular or trapezoidal lateral-surface sections arepreferably shaped identically to one another and are each in the form ofan isosceles triangle or trapezoid, in which case they adjoin oneanother by way of the legs of equal length.

A further preferred embodiment of the facing according to the inventionconsists in that a plurality of adjoining lateral-surface sections areproduced from a common plate by bending the plate for which purposebending using a laser beam is particularly suitable.

As is customary in the case of compaction rollers, it is also possiblein the case of a roller having facings according to the invention forthe facing to extend individually over the entire roller width or, inthe case of the individual axles, for in each case a plurality offacings to be arranged one beside the other with aligned axes ofrotation.

The invention is explained in more detail hereinbelow, with reference tothe drawing, using exemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawing, in schematic illustrations in each case:

FIG. 1 shows a perspective view of a two-axle ground-compaction rollerhaving in each case two facings according to the invention on each axle;

FIGS. 2a to 2 c show three facing lateral surfaces made up of differentnumbers of isosceles triangles, to be precise in isometric illustrationson the left in each case and in front views alongside these to theright;

FIGS. 3a to 3 c show three further facing lateral surfaces made up of adifferent number of isosceles triangles, it being the case that, in theindividual figures, the bottom three illustrations located one above theother show the relevant facing in views from above at different angledpositions about the axis of rotation of said facing, and the topillustration represents the respective facing as seen from the front;and

FIG. 4 shows an embodiment of the facing in the case of which the planarlateral-surface sections from which the lateral surface is made up arein the form of isosceles trapezoids.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The roller which is illustrated highly schematically in FIG. 1 has aroller frame 1 in which the customary drive units and control means areaccommodated. Beneath the roller frame 1, two pairs of roller facings,each mounted in a floating manner at the roller center, are arrangedequiaxially in each case, it being the case that, with at least one ofthe two axles, the facings are driven in any known manner by the maindrive unit in the roller frame 1 and vibratory units may be arranged ina known manner in said facings, it being possible for said vibratoryunits to make the facings 2 a, 2 b, 3 a (not shown in the drawing) and 3b vibrate. The individual facings 2 a, 2 b, 3 a and 3 b each havebearing plates 4 on both sides and a facing lateral surface 5, and,being rotatable about traveling axles 6, they are mounted on the facingcarrier (not shown in the drawing) which is located at the roller centerand, if appropriate, is steerable.

In the case of the embodiment according to FIG. 1, each facing lateralsurface 5 is made up of ten planar lateral-surface sections 7, of whicheach is in the form of an isosceles triangle, it being the case thatmutually adjacent lateral-surface sections 7 have in each case onetriangle side of equal length in common. The planar, triangularlateral-surface sections 7 are arranged such that in an alternatingmanner in the circumferential direction of the facing, on each end sideof the latter, a triangle vertex 7 a of a preceding lateral-surfacesection 7 is followed by a triangle side 7 b of the followinglateral-surface section 7, and each triangle side 7 b on one of the endsides of the facing has a triangle vertex 7 a on the opposite end sideof the facing located centrally opposite it.

FIGS. 2a to 2 c each show, in a perspective illustration on the left andin a front view on the right, various possible forms of lateralsurfaces, it being the case that according to FIG. 2c corresponds inprinciple to that used in the case of the facings according to FIG. 1,but is longer than the latter and could be used in the case of a facingwhich is mounted at both end sides and extends over the entire rollerwidth.

Further possible forms of facing lateral surfaces are illustrated inFIGS. 3a-3 c, it being the case that, in the individual figures, oneabove the other, the facing lateral surfaces 5 are represented in viewsfrom above in three angled positions each rotated by the amount of halfan edge, and are illustrated in a front view right at the top.

It can be seen from the front views in FIGS. 2a-2 c and FIGS. 3a-3 cthat the distance between the line of symmetry of each surface-areatriangle and the axis of rotation D of the facing increases linearlystarting from the triangle side 7 b on one facing-lateral-surface endside to the corner 7 a on the other, opposite facing-lateral-surface endside, with the result that, when the facing rolls on the ground, thebending lines between the surface-area triangles 7 are gradually pressedinto the ground, and then removed again, from one end side to the other.This ensures uninterrupted, usually slippage-free, high traction, itbeing the case that, even when vibrator units are used, the vibratoryforces are introduced in optimum fashion into the ground.

FIG. 4 shows an embodiment in the case of which the planarlateral-surface section 7′ comprise isosceles trapezoids, that is tosay, in comparison with the embodiments according to FIGS. 1 to 3 c, thecorner 7 a of the triangle has been cut off in this case, resulting in ashort trapezoid side 7 c is on the corresponding end side of the facing.This form of facing lateral surface can be produced more easily, be thisby bending the lateral-surface material at the bending lines duringproduction of a plurality of surface-area sections 7′ from one piece orby welding together individual trapezoidal surface-area sections at theabutting edges.

What is claimed is:
 1. A facing for rollers for the purpose of groundcompaction, the facing having a lateral surface formed from planarlateral-surface sections, wherein the planar lateral-surface sectionsare at least generally in the form of triangles, wherein the facingincludes opposed first and second ends, wherein each of the planarlateral-surface sections extend from the first end to the second end,wherein two adjacent planar lateral-surface sections have one side incommon and are arranged such that, in an alternating manner in thecircumferential direction of the facing on each of the opposed first andsecond ends of the facing, a relatively short portion of a precedingplanar lateral-surface section is followed by a relatively long portionof a following planar lateral-surface section that is located opposite arelatively short portion of the following planar lateral-surfacesection.
 2. The facing as claimed in claim 1, wherein thelateral-surface sections which are shaped identically to one another,are each at least generally in the form of an isosceles triangle andadjoin one another by way of triangle legs of equal length.
 3. Thefacing of claim 1, wherein said plurality of lateral-surface sectionsare produced from a common plate by the plate being bent.
 4. The facingof claim 1, wherein each of the lateral-surface sections is in the formof a trapezoid, and wherein the relatively short portions compriserelatively short trapezoid sides that are adjoined by two additionaltrapezoid sides, and wherein the relatively long portions are formed byrelatively long trapezoid sides.
 5. A facing for rollers for the purposeof ground compaction, the facing having a lateral surface formed fromplanar lateral-surface sections, wherein each of the lateral-surfacesections is in the form of a triangle, wherein two adjacentlateral-surface sections have one side in common and are arranged suchthat, in an alternating manner in the circumferential direction of thefacing on end sides of the facing, a relatively short portion of apreceding lateral-surface section is followed by a relatively longportion of a following lateral-surface section that is located oppositea relatively short portion of the following lateral-surface section, andwherein the relatively short portions comprise vertices of thetriangles.
 6. A facing for rollers configured to compact ground, thefacing comprising: a lateral surface that is formed from planarlateral-surface sections that are each at least generally in the form ofa triangle, wherein the facing includes opposed first and second ends,wherein each of the planar lateral-surface sections extend from thefirst end to the second end, wherein adjacent planar lateral-surfacesections each include one side in common, and wherein the planaradjacent lateral-surface sections are arranged such that, in analternating manner in the circumferential direction of the facing oneach of the opposed ends of the facings, a relatively short portion of apreceding planar lateral-surface section is followed by a relativelylong portion of a following planar lateral-surface section that islocated opposite a corresponding relatively short portion of thefollowing planar lateral-surface section.
 7. The facing of claim 6,wherein the rollers comprise vibratory rollers.
 8. A facing for rollersconfigured to compact ground, the facing comprising a lateral surfacethat is formed from planar lateral-surface sections each in the form ofa triangle, wherein adjacent lateral-surface sections each include oneside in common, wherein the adjacent lateral-surface sections arearranged such that, in an alternating manner in the circumferentialdirection of the facing on end sides of the facings, a relatively shortportion of a preceding lateral-surface section is followed by arelatively long portion of a following lateral-surface section that islocated opposite a corresponding relatively short portion of thefollowing lateral-surface section, and wherein the trianqularlateral-surface sections which are shaped identically to one another,are each in the form of an isosceles triangle and adjoin one another byway of triangle legs of equal length.
 9. A facing for rollers configuredto compact ground, the facing comprising a lateral surface that isformed from planar lateral-surface sections generally in the form of atriangle, wherein adjacent lateral-surface sections each include oneside in common, wherein the adjacent lateral-surface sections arearranged such that, in an alternating manner in the circumferentialdirection of the facing on end sides of the facings, a relatively shortportion of a preceding lateral-surface section is followed by arelatively long portion of a following lateral-surface section that islocated opposite a corresponding relatively short portion of thefollowing lateral-surface section, wherein the lateral-surface sectionsare in the form of trapezoids such that the adjacent lateral-surfacesections each include one trapezoid side having an equal length incommon, and wherein the adjacent lateral-surface sections are arrangedsuch that, in an alternating manner in the circumferential direction ofthe facing on the end sides of the facing, a relatively short trapezoidside of a preceding lateral-surface section is followed by a relativelylong trapezoid side of a following lateral-surface section that islocated opposite a corresponding relatively short trapezoid side of thefollowing lateral-surface section.
 10. The facing as claimed in claim 9,wherein the lateral-surface sections which are shaped identically to oneanother are each in the form of an isosceles trapezoid and adjoin oneanother by way of trapezoid legs of equal length.
 11. A rollerconfigured to compact ground, the roller including a plurality offacings, each facing comprising: a lateral surface that is formed fromplanar lateral-surface sections that are each at least generally in theform of a triangle, wherein the facing includes opposed first and secondends, wherein each of the planar lateral-surface sections extend fromthe first end to the second end, wherein adjacent planar lateral-surfacesections each include one side in common, wherein the adjacent planarlateral-surface sections are arranged such that, in an alternatingmanner in the circumferential direction of the facing on each of theopposed ends of the facing, a relatively short portion of a precedingplanar lateral-surface section is followed by a relatively long portionof a following planar lateral-surface section that is located opposite acorresponding relatively short portion of the following planarlateral-surface section, and wherein the plurality of facings arearranged one beside the other with aligned axes of rotation.
 12. Aroller configured to compact ground, the roller including a plurality offacings, each facing comprising: a lateral surface that is formed fromplanar lateral-surface sections that are each in the form of a triangle,wherein adjacent lateral-surface sections each include one side incommon, wherein the adjacent lateral-surface sections are arranged suchthat, in an alternating manner in the circumferential direction of thefacing on end sides of the facing, a relatively short portion of apreceding lateral-surface section is followed by a relatively longportion of a following lateral-surface section that is located oppositea corresponding relatively short portion of the followinglateral-surface section, wherein the plurality of facings are arrangedone beside the other with aligned axes of rotation, and wherein thetriangular lateral-surface sections which are shaped identically to oneanother are each in the form of an isosceles triangle and adjoin oneanother by way of triangle legs of equal length, and wherein each of therelatively short portions comprise a vertex of the associated triangle.13. A roller configured to compact ground, the roller including aplurality of facings, each facing comprising: a lateral surface that isformed from planar lateral-surface sections that are each generally inthe form of a triangle, wherein adjacent lateral-surface sections eachinclude one side in common, wherein the adjacent lateral-surfacesections are arranged such that, in an alternating manner in thecircumferential direction of the facing on end sides of the facing, arelatively short portion of a preceding lateral-surface section isfollowed by a relatively long portion of a following lateral-surfacesection that is located opposite a corresponding relatively shortportion of the following lateral-surface section, wherein the pluralityof facings are arranged one beside the other with aligned axes ofrotation, and wherein each of the lateral-surface sections is in theform of a trapezoid having a relatively short trapezoid side, twotrapezoid sides adjacent the relatively short trapezoid side, and arelatively long trapezoid side such at the adjacent lateral-surfacesections each include one trapezoid side in common, and wherein theadjacent lateral-surface sections are arranged such that, in analternating manner in the circumferential direction of the facing on theend sides of the facing, a relatively short trapezoid side of apreceding lateral-surface section is followed by a relatively longtrapezoid side of a following lateral-surface section that is locatedopposite a corresponding relatively short trapezoid side of thefollowing lateral-surface section, and wherein the plurality of facingsare arranged one beside the other with aligned axes of rotation.
 14. Theroller of claim 13, wherein the lateral-surface sections which areshaped identically to one another are each in the form of an isoscelestrapezoid and adjoin one another by way of legs of equal length.